Revenue Recognition (Capitalized Contract Costs) (Details) - USD ($) $ in Millions |
9 Months Ended | |
|---|---|---|
Sep. 30, 2026 |
Dec. 31, 2025 |
|
| Capitalized Contract Cost [Line Items] | ||
| Contract with Customer, Liability, Revenue Recognition Term | 1 year | |
| Vacation Ownership | ||
| Capitalized Contract Cost [Line Items] | ||
| Capitalized Contract Cost, Amortization Period | 3 years | |
| Travel and Membership | ||
| Capitalized Contract Cost [Line Items] | ||
| Capitalized contract costs | $ 21 | $ 16 |
| Balance Sheet Location [Axis]: us-gaap:OtherAssets | Vacation Ownership | ||
| Capitalized Contract Cost [Line Items] | ||
| Capitalized contract costs | 49 | 50 |
| Balance Sheet Location [Axis]: us-gaap:OtherAssets | Travel and Membership | ||
| Capitalized Contract Cost [Line Items] | ||
| Capitalized contract costs | 15 | 7 |
| Balance Sheet Location [Axis]: us-gaap:PrepaidExpenseCurrentAndNoncurrent | Travel and Membership | ||
| Capitalized Contract Cost [Line Items] | ||
| Capitalized contract costs | $ 6 | $ 9 |